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Energy

by Alison Martin

Whatever your opinion of the theories regarding Global Warming and carbon emissions, there's one good reason why you should add renewable energy to the harvest on your farm – money.

Underneath all the 'green' hoopla and jargon of this relatively new phenomenon, there are some simple facts which, when spelt out, might help those of us who are feeling blinded by science to start down the road to harnessing home grown energy.

The government has set incentives for commercial energy producers such as Scottish Power, Npower and E.on etc to move away from using conventional fossil fuels in traditional power stations to renewable energy sources. They will face enormous fines if they miss the targets set by the governement.

This effort has been divided into large scale production (by the power companies) and small scale production by organisations, businesses, communities and individuals, who are not traditionally engaged in the electricity market.

Power companies are now obliged by government legislation to buy electricity generated by renewable means from small scale producers at a fixed, premium rate. This allows many people to invest in small scale renewable electricity generation, in return for a guaranteed payment from the power companies.

The Feed-in Tarrif (written FiT or FIT) is the amount power companies pay small scale producers for electricity, and will benefit the producer in three ways:

1. A Generation Tariff providing a fixed price for each unit of electricity generated. The price will remain the same throughout the installation's eligibility for FiTs payments, and is index-linked
2. An Export Tariff providing a fixed payment for electricity sold to the grid

3. Reduced imports of electricity from the grid, leading to lower electricity bills and partial shielding from future price rises in electricity

Essentially this means that if you generate your own electricity, you can get paid for the electricity you use, plus any you export to the grid. Yes, you read it correctly, even if you don't export any electricity to the grid, and use all that you've generated yourself, you will still get paid for it.

And if during times of high demand, you have to buy electricity from the grid, it will cost you less. In many respects the term Feed-in Tarrif is not correct, in reality it is more of a 'electricity generation' tarrif.

FiTs were introduced in April this year in Scotland, England and Wales, and vary according to the type of technology used to generate the power and the size of the system in use. Different technologies are metered separately.

The FiT earned by the producer is tax free and the rate of the tariff is index-linked to the retail price index, meaning that it will track inflation. It is also guaranteed for 20-25 years, depending on which technology is used.

Farmers and landowners are particularly well placed to become small scale producers of renewable electricity. Large roof areas on sheds are ideal locations for banks of solar panels. Exposed poorer land? Maybe a wind turbine could make this pay. Even that stream or river flowing through your land could hold the key to cutting your electricity bill.

Another advantage for farms in general is that they're far enough from neighbours, who might object to apparatus like wind turbines in their view.

FiTs are available for electricity produced by Solar Photovoltaic (PV), Micro Hyrdo, Anaerobic digestion and domestic scale micro CHP.

Solar Photovoltaic Panels

Solar power can be harnessed in several ways, another common application is in solar thermal panels, which produce hot water. Solar PV converts sunlight directly to electricity by means of photovoltaic cells. A cell consists of layers of semi-conducting material, usually silicon. On exposure to light, silicon generates electricity. Since the electrical output of one cell is very small, multiple cells are connected together and encapsulated to form a module or 'panel.' Any number of panels can be connected together to give the desired scale of electrical output.

Solar photovoltaic equipment has no moving parts and so requires minimal maintenance. Summary photovoltaics require daylight, not direct sunlight, to convert solar radiation to electricity. These systems are neat, unobtrusive and can be fitted on flat or sloping roofs or mounted on the ground.

Wind Turbines

We're all familiar with wind mills running machinery to to grind corn, cut wood or pump water. Wind turbines employ the same concept, extracting energy from wind to generate electricity. Generally some form of power storage or alternate supply is required to cover windless periods. Before doing anything, check to see that your site really is windy enough to generate electricity.

Wind turbines vary according to the size of their output. Those used on a small scale for domestic electricity produce from 1-6kW. Medium scale models used to power community scale projects produce up to about 50kW, and large scale commercially operated turbines generate over 1MW.

Micro Hydro

Micro hydro refers to power produced from running water in a river or stream as opposed to large hydro electric schemes, which require large reservoirs. The potential power generation is based upon the consistency of the water flow, the speed of flow and/or the drop in height of water.

In most cases, private schemes generate between a few hundred watts and 25kW. They can be connected to the main electricity grid or alternatively can be used in an off-grid system where electricity is either used directly by appliances or is stored in batteries. Single households might be able to go completely 'off-grid' where there is a suitable hydro source nearby. In cases where excess power is generated this can also be sold back into the grid.

Many farms in Borders of Scotland are situated on the sites of old mills, and therefore maybe suitable for micro-hydro generation. However, costs are quite high and a pre-feasibility study will be needed to assess the situation.

The Energy Saving Trust (EST) should be the initial port of call for anyone wanting to find out more about electricity generation and how to join the scheme. The EST can be contacted on 0800 512 012, or at www.energysavingtrust.org.uk

Businesses looking to participate should contact the Carbon Trust to find out more on 0800 085 2005 or www.carbontrust.co.uk.